Modeling and control of power converters in weak and unbalanced electric grids

Grid converters increasingly affect power system operation due to the
increasing share of renewable energy sources and less conventional power
plants. This shift in power generation leads to converter-dominated
weak grids, which show critical stability phenomena but also enable
converters to contribute to grid stability and voltage support. This
thesis presents critical parts of converter controls and describes
models to assess their characteristics. These models are used to derive
design criteria and dedicated stability analysis methods for grid
converter controls.